Additive manufacturing, a type of which is known as three dimensional (3D) printing, is a process of manufacturing a three dimensional solid object from a model such as a digital model by an additive process in which material is layered, adhered, bonded or otherwise deposited successively until the solid object is formed. Such an approach is in contrast to traditional manufacturing techniques where articles are formed from the assembly of parts which themselves may be machined, cast or moulded.
Additive manufacturing provides numerous benefits over traditional manufacturing techniques, including technical benefits and commercial benefits. Technically, additive manufacturing allows virtually any arrangement of a three dimensional object to be created from a growing number of materials, including plastics, metals and ceramics. The arrangement can include complex features, even internally, since the additive approach to manufacturing is capable of generating complex structure. Additive approaches generate less waste compared to traditional approaches, provide increased consistency between articles of manufacture, improved speed of manufacture from initial design with minimal setup required, the advantages of novel structures and shapes and new combinations of materials.
Commercially, additive manufacturing provides considerable cost-savings over traditional manufacturing techniques, especially where a number of articles for manufacture is relatively small. For example, prototypes, proof-of-concepts, spare-parts and articles manufactured in isolated or remote locations, such as at sea or in orbit, are readily produced at low cost using additive manufacturing. The speed of manufacturing is also a benefit since a three dimensional article can be produced from a three dimensional design relatively rapidly and without bespoke or tailored rigging or manufacturing line.
Additive manufacturing covers a number of approaches. Extrusion deposition is an approach to additive manufacturing in which beads of material are extruded in a controlled manner either by way of a moveable extruder (“print-head”); a moveable table or support; or both. The extruded beads harden rapidly to form a layer or part of an article onto which further extrusion can take place. In this way the article is built-up additively.
An alternative approach is the selective fusing of granular materials such as a selective sintering or melting of metals or polymers. Using such an approach granular material is deposited in layers and selectively sintered, melted or bonded using, for example, convection heat, laser or electron beam. The selection is made based on a three dimensional model of the article in a layered manner. In this way the article is built-up additively.
Use of additive manufacturing to produce electrical or electronic devices has been severely constrained since additive manufacturing is not suitable for manufacturing complex modern electronic components from many disparate materials. While additive manufacturing has found applications in the printing of planar circuit board layouts with component sockets and interconnects in combination with trenches or routes for electrical connections, there is currently a requirement for placement, installation and/or assembly of electrical and electronic components following the additive manufacturing process. This requirement for post-manufacture assembly and/or installation has the considerable disadvantage that component locations, sockets and routes must be accessible in an additively-manufactured product. Accordingly, the hugely beneficial characteristics of additive-manufacturing of accurately producing complex, internalised and potentially inaccessible structures are entirely lost in the electronic field. Furthermore, the requirement for post-manufacture assembly and/or installation imposes burdens of additional manufacturing steps that considerably erode the benefits of additive manufacturing.
Thus it would be beneficial to produce electronic devices using additive manufacturing approaches without the aforementioned disadvantages.
The present invention accordingly provides, in a first aspect, A 3D printed apparatus having a gas filled sealed cavity containing at least two 3D printed cathodes and a 3D printed anode spaced from the cathodes such that a continuous electric discharge of the gas stimulated between at least one of the cathodes and the anode provides a Boolean function output at the anode corresponding to electrical input signals at two of the cathodes.
Thus, embodiments of the present invention provide for the production of a three dimensional article by way of the additive manufacturing process. The use of such a manufacturing process allows for the production of a three dimensional article having potentially complex internal characteristics with the integration of active and/or logic gate electronic components such as diodes, triodes and logic gates within the fabric of the article. Due to the production and integration of active electronic components as part of the article manufacturing process there is no requirement for post-production assembly or installation of electronic components. Thus, manufacture of articles with installed electronic components can occur contemporaneous with the manufacture of the substantive three dimensional structure of the article. This relieves the manufacturing process from considerations of post-production assembly and installation of electronic components, such as burden approaches of the prior art that require multi-part manufacture with accessible integration interfaces and the like. Further, the cost of manufacture is dramatically reduced due to the use of additive manufacturing process, especially where small numbers of articles are required such as in prototyping or proof-of-concept manufacture, or in remote or inaccessible locations such as in orbit or space.
The inclusion of logic gate electronic components within the fabric of a three dimensional article reduces the overall weight of the article due to the absence of additional components and/or appendages. Furthermore, articles can be made more streamlined, with electronic componentry embedded within the article, such as internally in an imperceivable, undetectable and/or unobtrusive location within the article. Where the active electronic component is embedded in the article, the component can be protected from exposure to fluids such as moisture or air. The ability of additive manufacturing to produce articles on the micro-scale provides for potentially ‘intelligent’ (in the sense of including electronic componentry) articles in all manner of applications, including: electronics embedded within cellular telephone cases or covers; electronics embedded within cable sheaths; electronics embedded within fabric or clothing; electronics embedded within cases, covers, walls or other structural elements of other devices such as consumer or entertainment devices; electronics in spare-parts; and the like.
The removal of the requirement for accessibility of an electrical circuit and component locations for post-manufacturing assembly or installation dramatically redefines how electrical circuits and electronic devices can be designed and implemented in articles of manufacture. Embodiments of the present invention provide for true three-dimensional arrangements of active and/or logical electronic components and the connections therebetween without a requirement for accessibility of individual components or connections. This provides for an increase in the efficient use of space or volume of an article, and potentially for the reuse of active electronic components where appropriate by circuits of the same device under control. Vertical interconnects can provide for three dimensional processing elements such as cubic or other three dimensional arrangements of electronic components and circuits. A layered architecture of electronic components can be produced with layers of active electronic components within a single three dimensional article. Common services such as provision of power, dissipation of power, dissipation of thermal energy and the like can be provided by strata of service layers included as part of the additive manufacturing process, such as metal layers for power supply or layers of thermally efficient conducting materials for heat dissipation or transfer. Conceivably, channels and conduits can be provided, manufactured as part of the additive manufacturing process, for the communication of fluids such as coolants or gases to further provide services to electronic components such as the transfer of heat from within the article, such as heat generated by the active electronic components.
A particular advantage of the use of thermionic and continuous electric discharge logic electronic components is the benefits of such components over silicon equivalents such as silicon transistors. Additively manufactured components in accordance with embodiments of the present invention have considerable robustness and provide improved analogue signal transfer properties.
Preferably the apparatus further comprises a 3D printed stabilising resistor as a resistive material electrically coupled to the anode to stabilise the continuous electric discharge.
Preferably the continuous electric discharge of the gas occurs as an electric arc.
Preferably the cavity contains two cathodes such that the Boolean function is an OR function.
Preferably the anode is an output anode and the at least two cathodes include: a control cathode spaced opposing the output anode; and a first and second input cathodes to receive the input signals via 3D printed electrical signal paths, the apparatus further comprising at least two drain anodes each spaced opposing a respective one of the input cathodes, wherein a potential difference between the control cathode and output anode stimulates the continuous electric discharge allowing current to flow therebetween, wherein a potential difference between one of the input cathodes and a respective drain anode is insufficient to deflect the continuous electric discharge allowing current to flow via the output anode, and wherein a potential difference between both of the input cathodes and the respective drain anodes is sufficient to deflect the continuous electric discharge preventing current flowing via the output anode, such that the Boolean function output at the anode corresponds to a logical NAND operation on the input signals at the input cathodes.
Preferably an axis through the control cathode and the output anode is substantially perpendicular to an axis between the first input cathode and respective drain cathode and also perpendicular to an axis between the second input cathode and respective drain anode.
Preferably the apparatus further comprises a 3D printed circuit.
The present invention accordingly provides, in a second aspect, a 3D printed article comprising one or more of the 3D printed apparatus described above as NAND gates within the fabric of the article wherein the NAND gates are arranged to form any number of one or more of: OR, NOT, AND, NOR and XOR logic gates.
The present invention accordingly provides, in a third aspect, a method of manufacturing an article with integral logic gate electronic component comprising: using an additive manufacturing process to: a) form an electrically non-conductive substrate; b) form an electrically non-conductive perforated layer having a cavity; c) form electrically conductive anode and cathode elements spaced in the cavity including at least two cathodes; d) deposit a conductive electrical connection to each of the elements sufficient to imparting an electrical potential difference between the elements; e) form an electrically non-conductive sealing layer atop the perforated layer so as to retain and seal the cavity in the perforated layer, wherein the cavity contains gas and wherein the electrical potential difference is sufficient to stimulate a continuous electric discharge of the gas between at least one of the cathodes and the anode to provide a Boolean function output at the anode corresponding to electrical input signals at two of the cathodes.
Preferably forming one or more of: the substrate; perforated layer; and sealing layer includes forming a channel providing fluid communication between the cavity and a fluid port of the article, wherein the fluid port via which the gas can be inserted into the cavity.
Preferably the additive manufacturing process takes place within a sealed atmosphere constituted substantially of an inert gas so as to encase the inert gas in the cavity on formation of the sealing layer.
Preferably the anode is positioned at a side of the cavity opposing a side at which the cathodes are positioned such that the logic gate constitutes a Boolean OR function of the electrical input signals.
Preferably the anode is an output anode and the at least two cathodes include: a control cathode formed spaced opposing the output anode; and a first and second input cathodes formed to receive the input signals via 3D printed electrical signal paths, the method further comprising forming at least two drain anodes each spaced opposing a respective one of the input cathodes, wherein a potential difference between the control cathode and output anode stimulates the continuous electric discharge allowing current to flow therebetween, wherein a potential difference between one of the input cathodes and a respective drain anode is insufficient to deflect the continuous electric discharge allowing current to flow via the output anode, and wherein a potential difference between both of the input cathodes and the respective drain anodes is sufficient to deflect the continuous electric discharge preventing current flowing via the output anode, such that the Boolean function output at the anode corresponds to a logical NAND operation on the input signals at the input cathodes.
Preferably the additive manufacturing process includes one or both of an extrusion deposition process and a granular material binding process.
Preferably at least one of the: electrically non-conductive substrate; perforated layer; and sealing layer are formed in ceramic.
Preferably at least one of the anode and the cathodes are formed from a gallium alloy.
The present invention accordingly provides, in a fourth aspect, an article with integral logic gate electronic component manufactured by the process described above.
The present invention accordingly provides, in a fifth aspect, an additive manufacturing apparatus for manufacturing an article with integral active electronic component, the apparatus comprising: a computer system; a first additive manufacturing component adapted to form electrically non-conductive three dimensional structures; a second additive manufacturing component adapted to form electrically conductive three dimensional structures; wherein the first and second additive manufacturing components are operable under control of the computer system, the computer system being adapted to control the components to: a) form an electrically non-conductive substrate; b) form an electrically non-conductive perforated layer having a cavity; c) form electrically conductive anode and cathode elements spaced in the cavity including at least two cathodes; d) deposit an electrically conductive electrical connection to each of the elements sufficient to imparting an electrical potential difference between the elements; e) form an electrically non-conductive sealing layer atop the perforated layer so as to retain and seal the cavity in the perforated layer, wherein the cavity contains gas and wherein the electrical potential difference is sufficient to stimulate a continuous electric discharge of the gas between at least one of the cathodes and the anode to provide a Boolean function output at the anode corresponding to electrical input signals at two of the cathodes.
The present invention accordingly provides, in a sixth aspect, a computer system for controlling an additive manufacturing apparatus, the additive manufacturing apparatus being adapted to manufacture three dimensional structures from both electrically non-conductive and electrically conductive materials, the computer system being operable to control the additive manufacturing apparatus to perform the method described above.